Non-circular resection device and endoscope

ABSTRACT

A proximal housing for a full-thickness resection device (FTRD) is provided with a plurality of chambers through which fasteners are introduced into a portion of tissue to be resected. The proximal housing has a noncircular cutout opposite the plurality of chambers to receive a noncircular endoscope. The proximal housing also is provided with a resection cavity into which the tissue to be resected is to be received. In addition, shaft openings are provided through which mounting shafts may be inserted. A noncircular endoscope is also disclosed for insertion into the cut-out whereby the endoscope has passages to house the functions of remote viewing, illumination, insulation and irrigation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a full-thickness resection device (FTRD) for performing localized resections of lesions in tubular organs, particularly the colon. The present invention has particular application to transanal and transoral surgical procedures, although it is not limited thereto.

2. Description of the Related Art

A resection procedure involves excising a portion of an organ, approximating the surrounding tissue together to close up the hole created by the excision, and removing the excess tissue. Various conventional devices and procedures are available for resectioning lesions in tubular organs.

For example, several known resection devices and procedures require at least one incision in an area near the portion of the organ to be excised for access to the lesion or treatment site (because, for example, the resectioning device may lack steering and/or viewing capabilities). Thus, the incision is required to allow the physician to access the organ section to be excised and guide the device to that section. Alternatively, when the organ section to be excised is beyond the reach of the surgical device, or the surgical device is not flexible enough to wind through the organ to the site to be excised, an incision will be required to position the device for the procedure. Of course, these incisions are painful and may involve a partial or entire loss of mobility while recuperating from the incision, in addition to recovering from the tubular resectioning procedure itself. In addition, the time required to recover from such a procedure is often longer than for procedures which do not require incisions.

One type of conventional resection procedure utilizes a circular stapling instrument in which a tubular section of a tubular organ is excised, resulting in the tubular organ being separated into a first segment and a second segment. The end sections of the first and second segments are then individually tied in a purse-string fashion, approximated, stapled, and the “purse-stringed” end sections are then cut off. In this full circle resectioning procedure, at least one separate invasive incision must be made near the section to be excised in order to cut and individually tie the separate end sections of the organ. Also, a separate incision is necessary to place one part of the resectioning device in the first segment and a corresponding second part of the device in the second segment so that the device can then bring the first and second segments together to re-attach the organ sections back together. A first of these separate parts may generally include a staple firing mechanism while the second part includes an anvil for forming the staples. Thus, this type of resectioning procedure involves the drawbacks mentioned above in regard to procedures requiring invasive incisions. In addition, the separation of the organ into two segments creates the risk of spillage of non-sterile bowel contents into the sterile body cavity, which can cause severe infection and possibly death.

An alternative resectioning device includes a stapling and cutting assembly on a shaft which can be bent or formed into a desired shape and then inserted into a patient's body cavity. Once the shaft has been bent into the desired shape, the rigidity of the shaft ensures that that shape is maintained throughout the operation. This arrangement limits the effective operating range of the device as the bending of the shaft into the desired shape before insertion and the rigidity of the shaft once bent require the physician to ascertain the location of the organ section to be removed before insertion, and deform the shaft accordingly. Furthermore, the rigidity of the shaft makes it difficult to reach remote areas in the organ—particularly those areas which must be reached by a winding and/or circuitous route (e.g., sigmoid colon). Thus, an incision may be required near the organ section to be excised in order to position the device at the organ section to be excised.

Currently such FTRD's incorporate standard endoscopes available from various manufacturers. These standard endoscopes are circular in shape, and while a circular shape is desirable in many conventional applications where the endoscope is used independenty, with FTRD's, a circular endoscope, for example, takes up significant space in the body lumen. This can result in a sample having a smaller size than desired. A circular endoscope also may not have sufficient flexibility to bend to a desired location.

SUMMARY OF THE INVENTION

In accordance with the invention, a proximal housing for a full-thickness resection device (FTRD) is provided with a plurality of chambers through which fasteners are introduced into a portion of tissue to be resected. The proximal housing has a noncircular cut-out opposite the plurality of chambers to receive a noncircular endoscope. The proximal housing also is provided with a resection cavity into which the tissue to be resected is to be received. In addition, shaft openings are provided through which mounting shafts may be inserted.

According to another aspect of the invention, the plurality of chambers is configured so as to provide a substantially elliptical fastener pattern.

According to yet another aspect of the invention, the fasteners used are staples.

According to another aspect of the invention, a noncircular endoscope is also disclosed that is substantially the same shape as the cutout for insertion into the cut-out whereby the endoscope has passages to house the functions of remote viewing, lighting, insufflation and irrigation.

According to another aspect of the invention, the noncircular endoscope is elliptical in shape.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a perspective view showing a full-thickness resection device according to an embodiment of the present invention;

FIG. 2 is a perspective view showing the device of FIG. 1 mounted on an endoscope according to an embodiment of the present invention;

FIG. 3 is a perspective view showing the device of FIG. 1 with a grasper mechanism extending therefrom;

FIG. 4 is a perspective view showing a drive mechanism of FIG. 1;

FIG. 5 is a perspective view showing the device of FIG. 1 with a tapered end for ease of insertion;

FIG. 6 is a cross-sectional view of a proximal housing of a full-thickness resection device, according to an embodiment of the present invention;

FIG. 7 is a cross-sectional view showing an endoscope to be used with the device of FIG. 6.

DESCRIPTION OF THE EMBODIMENTS

The present invention is directed to a non-circular endoscope and corresponding FTRD. These non-circular devices have numerous advantages over existing circular devices. For example, the non-circular shape allows the device to take up less space within the body lumen into which it is being inserted. The non-circular endoscope also provides a more efficient means of packaging the combination of the device and endoscope. The more efficient utilization of space enables a device that can capture larger specimen sizes than an equivalent circular endoscope would permit. In addition, a non-circular endoscope for use with an FTRD may be more flexible and therefore more easily bend forwards a desired location, due, for example, to the smaller cross-sectional area of the endoscope. In preferred embodiments, the endoscope is shaped for particular use in combination with devices that perform a full thickness resection or similar procedure. In addition, the shape of a staple cartridge and anvil of the devices has a more elliptical, non-circular staple pattern that also provides further advantages.

Reference will now be made in detail to the present embodiments of the invention, examples of which is illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

As shown in FIGS. 1 and 2, an FTRD comprises a working head assembly 2 which may be connected to a distal end 4 a of a sheath 4. The proximal end of the sheath 4 may be connected to a control handle 6. In operation, the entire apparatus is mounted onto an endoscope 8, having a proximal end 8 a and a distal end 8 b, by passing the endoscope 8 through the control handle 6, the sheath 4, and the working head assembly 2, as shown in FIG. 2. The endoscope 8 is then inserted into a body orifice to locate a lesion in the tubular organ under visual observation (usually while insuflating the organ). Once the lesion has been located, the working head assembly 2 and the sheath 4 are slidably advanced along the endoscope 8 into the tubular organ until the working head assembly 2 is in a desired position adjacent to the lesion. Those skilled in the art will understand that in an alternative embodiment, the working head assembly 2 may also be detachably coupled to a distal end of the endoscope 8, and the entire arrangement may then be inserted into the body orifice under visual observation.

As shown in FIG. 1, the working head assembly 2 comprises an anvil member 10 coupled to a distal end 12 a of a proximal housing 12. The anvil member 10 has a substantially crescent-shaped cross-section (i.e., the outer edge 18 of the anvil member 10 substantially forms a portion of a first ellipse with a second smaller elliptical cut-out 13 formed within the first ellipse) with a distal face 16 and a larger proximal face opposite the distal face. The cut-out 13 of the anvil member 10 is included to allow the endoscope 8 to be slid through the entire working head assembly 2 so that the endoscope 8 may be advanced into the body passage allowing the working head assembly 2 to later be advanced into the body to the lesion. In addition, the cut-out 13 also provides forward vision via the endoscope 8. Thus, any shape of the cut-out 13 may be selected which is large enough to accommodate the endoscope 8, with a larger cut-out providing a larger field of vision. An outer surface 18 of the anvil member 10 extends substantially parallel to a central axis of the working head assembly 2 while the proximal and distal faces of the anvil member 10 extend in planes substantially perpendicular to the central axis. The outer surface 18 is joined to the distal face 16 by a tapered portion 5.

As shown in FIG. 3, the proximal face of the anvil member 10 includes a first cavity 37 and a rim 41 encircling the first cavity 37. A plurality of staple-forming grooves 19 are arranged in two offset rows on the rim 41 of the anvil member 10 and an elliptical guiding slit 21 extends radially within the rows of grooves 19. The rim 41 protrudes from the remainder of the proximal face so that a shallow cavity is formed on the proximal face.

The anvil member 10 is coupled to the proximal housing 12 by means of two mounting shafts 20 a and 20 b, which may be substantially cylindrical. Each mounting shaft 20 a, 20 b is coupled to the proximal face 14 of the anvil member 10 on a respective one of two horns 22 a, 22 b formed by the crescent-shaped anvil member 10. Although the anvil member 10 is shown fixedly coupled to the mounting shafts 20 a, 20 b, those skilled in the art will understand that the anvil member 10 may also be pivotally coupled to the mounting shafts 20 a, 20 b in order to provide a greater field of vision through the endoscope 8, as shown in FIG. 3. In this pivoted-type arrangement, the anvil member 10 is angled in a first configuration so that the horns 22 a, 22 b are closer to the distal end 12 a of the proximal housing than the rest of the anvil member 10. Then, as the anvil member 10 is drawn towards the distal end 12 a of the proximal housing 12, the anvil member 10 would be pressed against the distal end 12 a beginning with the horns 22 a, 22 b, which would cause the anvil member 10 to pivot until the proximal face 14 of the anvil member 10 is parallel to the distal end 12 a.

As shown in FIG. 1, the mounting shafts 20 a, 20 b are slidably received in mounting holes 26 a, 26 b, which have a size and shape substantially corresponding to the size and shape of the mounting shafts 20 a, 20 b and which run axially through the proximal housing 12. The mounting shafts 20 a, 20 b are preferably movable axially proximally and distally within the mounting holes 26 a, 26 b between a proximal most position in which a tissue gripping gap of a first predetermined width is formed between the rim 41 and the distal end 12 a of the proximal housing 12, and a distal most position in which a tissue receiving gap of a larger second predetermined width is formed between the rim 41 and the distal end 12 a of the proximal housing 12. The second predetermined width should preferably be more than twice the thickness of a wall of the organ being resectioned so that a section of the tubular organ may be pulled into a resectioning position between the anvil member 10 and the proximal housing 12.

As shown in FIG. 4, the proximal end of at least one of the mounting shafts 20 a and 20 b is coupled to a drive mechanism 92 provided within the proximal housing 12. The drive mechanism 92 is composed of a yoke 93 and a drive shaft 95. The yoke 93 is slidably received within the proximal housing 12 for longitudinal movement along the axis of the proximal housing 12 so that, when the anvil member 10 is in the proximal most position, the yoke 93 is in a corresponding proximal most position and, when the anvil member is in the distal most position, the yoke 93 is in a corresponding distal most position.

The yoke 93 may be substantially elliptical with a substantially rectangular cross-section. Although the ellipse formed by the yoke 93 in FIG. 4 forms substantially a quarter arc of a ellipse, the yoke 93 may form a larger ellipse based upon the interior accommodations of the proximal housing 12 and the position of the mounting shafts 20 a, 20 b. The mounting shaft 20 a may preferably be coupled to the yoke 93 at a first end 93 a of the yoke 93, and the mounting shaft 20 b may be coupled at a second end 93 b of the yoke 93. A shaft hole 97, having a diameter substantially corresponding to a diameter of a complementarily threaded distal end 95 a of the drive shaft 95, extends through the yoke 93 at a point substantially midway between the first end 93 a. and second end 93 b. Thus, when the drive shaft 95 is rotated, the threaded distal end 95 a engages the shaft hole 97 to move the yoke 93 proximally or distally (in dependence upon the direction of rotation of the drive shaft 95).

The distal end 95 a of the drive shaft 95 should preferably be threaded over a first section 95 t substantially corresponding in length to at least the distance between the proximal and distal most yoke positions, while a remainder portion 95 r may have no threads thereon. The drive shaft 95 may have an increased cross-section in the areas immediately adjacent to the threaded first section 95 t (proximally and/or distally of section 95 t), thereby limiting the movement of the yoke 93 to the first section 95 t. Those skilled in the art will understand that the drive shaft 95 is rotatably mounted within the proximal housing 12 so that it may only rotated and may not move relative to the proximal housing 12. The drive shaft 95 extends to a proximal end 95 b which is coupled to a drive cable 90 which extends to the control handle 6 through the sheath 4. The drive cable 90 may run axially along the peripheral interior of the sheath 4. Those skilled in the art will understand that the sheath 4 is torsionally stiff to resist the torque forces from the drive cables rotating therein. However, the sheath 4 is longitudinally flexible to so that it may be slidably advanced along the endoscope 8, while minimizing interference with the operation of the endoscope 8 and trauma to surrounding tissue. The sheath 4 is constructed similar to other known endoscope insertion tubes, which are flexible yet allow the transfer of forces to swivel the distal end of the endoscope 8 in multiple directions and the torqueable rotation of the endoscope.

In operation, the user advances the endoscope 8, with the working head assembly 2 received therearound, to a portion of tissue to be resectioned until the working head assembly 2 is in a desired position adjacent to the tissue to be resectioned. The user may then apply a force to the control handle 6 to rotate the drive cable 100, as seen in FIG. 4, which in turn rotates the drive shaft 95 to advance the yoke 93 and the anvil member 10 distally away from the distal end 12 a of the proximal housing 12. As shown in FIG. 3 when the anvil member 10 has reached the distal most position, a known grasping device 98 is advanced through the sheath 4 and through the working head assembly 2 to enter the gap between the anvil member 10 and the distal end 12 a via one of the grasper holes 32 and 33. Although the device in FIG. 3 is shown using a duodenoscope as the endoscope 8, those skilled in the art will understand that other types of endoscopes may also be used, such as, for example, gastroscope, colonoscope, etc.

As shown in FIG. 1, at least the distal end 12 a of the proximal housing 12 has a cross-section corresponding in size and shape to the proximal face 14 of the anvil member 10, including a cut-out 29 substantially corresponding in size and shape to the cutout 13 of anvil member 10. The cut-out 29 is provided to receive the endoscope 8 therein and allow the proximal housing 12 to be slidably advanced along the endoscope 8. Of course, those skilled in the art will understand that the shape of the outer surface of the working head assembly 2 may be selected in order to accommodate various desired resectioning shapes, and the shape of the anvil member 10 may preferably be selected to form a continuous surface when positioned adjacent to the proximal housing 12 to facilitate advancing the working head assembly to into and removing it from, body passages. It is preferable that the working head assembly have a maximum diameter at any point between 15 mm and 40 mm.

A tissue receiving cavity 30 is formed substantially centrally in the distal end 12 a of the proximal housing 12 to facilitate the drawing of sections of tubular organs into the gap between the anvil member 10 and the distal end 12 a. Those skilled in the art will understand that the depth of the cavity 30 may vary depending on the amount of tissue to be pulled into the cavity 30 and the size of the proximal housing 12. Two grasper holes 32 and 33 extend axially, preferably slightly off-center from the longitudinal axis of the proximal housing 12. The grasper holes 32 and 33 may each receive a grasping device 108 advanced from the control handle 6, through the sheath 4, and through a respective one of the grasper holes 32 and 33.

In operation, either one or two grasping devices 98 may then be used to pull a section of the tubular organ between the anvil member 10 and the distal end 12 a of the proximal housing 12 and into the cavity 30. A third grasping device 98 may also be inserted through the working channel of the endoscope 8 to provide another means of positioning the organ section between the anvil member 10 and the proximal housing 12. Of course, those skilled in the art will understand that any desired instrument may be advanced to the gap between the anvil member 10 and the distal end 12 a through any of the grasper holes 32, 33 and the working channel of the endoscope 8.

A plurality of staple slits 34 are preferably disposed in two offset substantially elliptical rows extending along the periphery of the distal end 12 a of the proximal housing 12. The staple slits 34 extend from an area adjacent to the mounting shaft 26 a to an area adjacent to the other mounting shaft 26 b. The plurality of staple slits 34 may be arranged so that when the anvil member 10 is in the proximal most position, each of the staple slits 34 is aligned with a corresponding one of the staple-forming grooves 19.

When the device is configured for operation, a plurality of staples is received within the working head assembly 2 with each of the staples being aligned with a respective one of the staple slits 34. The staples are then sequentially fired from the respective staple slits 34 by an actuating mechanism (not shown) disposed in the proximal housing 12.

A substantially elliptical blade slit 36 extends substantially radially within the staple slits 34 so that, when the anvil is in the proximal most position, the blade slit 36 is aligned with the guiding slit 21 on the anvil member. As shown more clearly in FIG. 4, extensions 84 a and 84 b of the blade slit 36 extend into blade housings 74 a and 74 b, respectively, which project distally from the distal end 12 a of proximal housing 12. The blade housings 74 a and 74 b are preferably situated so that when the anvil member 10 is in its proximal most position, the blade housings 74 a and 74 b contact portions 43 a and 43 b of the rim 41 of the anvil member 10. The extension of the blade housings 74 a and 74 b from the proximal housing 12 is preferably selected so that when the blade housing devices 74 a and 74 b engage the remainder portions 43 a and 43 b of the rim 41 (thereby stopping a proximal movement of the anvil member 10 and defining the proximal most position thereof), a gap is formed between the anvil member 10 and the distal end 12 a of a length sufficient to allow the anvil member 10 to securely hold a portion of the organ against the proximal housing 12 without crushing and damaging the portion of the organ.

When positioned at one end of the blade slit 36 (i.e., in one of the extensions 84 a and 84 b), a cutting blade (not shown) is preferably completely enclosed within the respective one of the blade housing devices 74 a and 74 b and the guiding slit 21, so that the cutting blade does not cut any tissue until the physician intentionally operates the blade. When the physician operates the blade, the blade is driven from its initial position received within one of the extensions 84 a and 84 b around the blade slit 36 with its cutting edge facing a direction of movement, until the blade is received into the other one of the extensions 84 a and 84 b. Thus, after a cutting operation has been performed, the blade is once again prevented from inadvertently injuring the patient.

As can be seen in the prior art devices utilizing a circular endoscope, the endoscope occupies significant space within the FTRD and also encroaches upon the resection cavity. With the prior art devices, in order to provide a cavity of the size necessary to perform the desired surgical procedure, the overall size of the FTRD must be made larger.

FIG. 6 shows a cross section of a proximal housing 112 of an FTRD, and is configured to receive a non-circular endoscope within cut-out 129. Proximal housing 112 also contains mounting holes 126 a and 126 b as well as mounting shafts.

As can be seen, cut-out 129 does not extend into cavity 130 as much as in the prior art devices, thus allowing the overall size of proximal housing 112 to be reduced. In addition, the elliptical shape of the head provides a more desirable elliptically shaped staple pattern for the staples ejected from chambers 134 than the partial circular pattern of the prior art devices.

Endoscope 108, as seen in FIG. 7, is an endoscope of the present embodiment to fit within cut-out 129. Rather than using a standard circular endoscope of the prior art devices that may provide more chambers than what is necessary for a full-thickness resection procedure, the current invention relates to an endoscope that provides only what is needed for the desired procedure. Endoscope 108 can be provided with as few as four chambers to house the functions used to perform this procedure: remote viewing, lighting, insufflation and irrigation.

According to the present embodiment, endoscope 108 has an elliptical shape to fit within cut-out 129 of proximal housing 112. Those skilled in the art would understand that other noncircular shaped endoscopes could be utilized that provide the same low-profile shape that the elliptical shape provides. Provided within endoscope 108 are five chambers 108 a-108 e. Chamber 108 c preferably houses the optics portion of the endoscope. Chambers 108 b and 108 d contain light sources to illuminate the area in which the procedure is to be performed. Chambers 108 a and 108 e may provide the insufflation and irrigation functions of the endoscope, respectively, although one of ordinary skill in the art could comprehend that these functions may be reversed. In operation an FTRD utilizing proximal housing 112 will function in the same manner as the prior art FTRD's.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 

1-14. (Canceled).
 15. An operative head of a device for endolumenally treating a full-thickness portion of a wall of an organ, comprising: a housing having an endoscope channel extending therethrough for slidably receiving an endoscope therein, cross-sectional shape of the endoscope channel being non-circular, the housing including a stapling mechanism having a plurality of staple firing chambers disposed around a portion of a periphery of the housing; and an anvil member moveable relative to the stapling mechanism between a tissue receiving position and a tissue stapling position, the anvil member being further moveable relative to the housing between a staple forming configuration in which staple forming grooves thereof are aligned with corresponding ones of the staple firing chambers and a high visibility configuration providing a field of vision of an endoscope received in the endoscope channel greater than that provided when the anvil member is in the staple forming configuration.
 16. The device according to claim 15, wherein a cross section of the endoscope receiving channel is substantially elliptical.
 17. The device according to claim 15, wherein the staple firing grooves extend along a substantially elliptical path.
 18. The resection device according to claim 15, wherein the staple forming grooves are disposed along a substantially elliptical path.
 19. The resection device according to claim 15, wherein the anvil member is coupled to the stapling mechanism by at least one mounting member slidably received within the housing for movement between the tissue receiving and stapling positions and wherein the anvil member is pivotally attached to a distal end of the at least one mounting member for movement between the staple forming and high visibility configurations.
 20. The resection device according to claim 18, wherein, when in the staple forming configuration, the anvil member is substantially parallel to a distal face of the housing, the staple firing chambers being arranged on the distal face of the housing.
 21. The resection device according to claim 15, further comprising a drive mechanism for moving at least one of the anvil member and the stapling mechanism relative to one another between the tissue receiving and the tissue stapling positions.
 22. The resection device according to claim 20, wherein the drive mechanism further comprises a yoke operatively connected to the anvil member and a drive shaft geared to the yoke such that rotation of the drive shaft results in translation of the yoke relative to a longitudinal axis of the housing.
 23. The resection device according to claim 21, further comprising a hand control coupled to the drive shaft so that, when the hand control is operated, the drive shaft is rotated.
 24. The resection device according to claim 15, wherein the resection housing has a substantially non-circular cross section.
 25. The resection device according to claim 24, wherein the cross section of the resection housing is substantially elliptical.
 26. A method for treating a full-thickness portion of a wall of a hollow organ, comprising: inserting a housing of a resection device into a hollow organ via a naturally occurring body orifice to a location proximate to a target portion of tissue to be resected, the housing including a non-circular endoscope channel, a tissue cutting mechanism, a stapling mechanism having a plurality of staple firing chambers disposed in a substantially elliptical configuration around a portion of a periphery of the housing and an anvil moveable relative to the stapling mechanism between tissue receiving and tissue stapling positions; advancing a substantially non-circular endoscope into the endoscope channel; moving the stapling mechanism to the tissue receiving position; drawing the target portion of tissue between the anvil and the stapling mechanism; moving the anvil to the stapling position; firing a plurality of staples from the staple firing chambers through the target portion of the tissue against the anvil; and actuating the knife to cut the target portion tissue from the stapled tissue.
 27. The method according to claim 26, further comprising moving the anvil by turning a drive shaft geared to a yoke operatively connected to the anvil.
 28. The method according to claim 27, further comprising turning the drive shaft with a hand control which remains outside the body.
 29. The method according to claim 26, further comprising advancing a substantially elliptical endoscope into a substantially elliptical receiving channel.
 30. The method according to claim 26, wherein the resection housing has a substantially elliptical cross section.
 31. The method according to claim 26, wherein the target portion of tissue is drawn between the anvil and the stapling mechanism by manipulating grasping devices.
 32. The method according to claim 31, further comprising drawing the target portion of tissue into a tissue receiving cavity of the housing.
 33. A system for endolumenally treating a full-thickness portion of an organ, comprising: a non-circular endoscope; and a housing slidably receiving the endoscope within a non-circular endoscope channel, the housing including a stapling mechanism having a plurality of staple firing chambers disposed around a portion of a periphery of the housing along a substantially elliptical path and an anvil moveable relative to the stapling mechanism between a tissue receiving position and a tissue stapling position.
 34. The system according to claim 33, wherein the anvil translates longitudinally relative to the stapling mechanism between the tissue receiving and tissue stapling positions.
 35. The system according to claim 33, wherein the anvil moves between a staple forming configuration and a high visibility configuration in which a field of vision of the endoscope is increased relative to that when the anvil is in the staple forming configuration.
 36. The system according to claim 33, further comprising a yoke operatively connected to the anvil and a drive shaft geared to the yoke so that rotation of the drive shaft causes translation of the yoke along a longitudinal axis of the housing. 